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Use the GDC 2021 Session Viewer to browse and sort the ever-growing list of sessions by day, time, pass type, topic, and format. All registered attendees will be able to build their personal schedule directly within the event platform, once live early July 2021. All times are listed in Pacific Time.

Math In Game Development Summit: Getting There in Style: Intro to Interpolation and Control Systems

Fletcher Dunn  (Programmer, Valve)

Date: Tuesday, July 20

Time: 8:30am - 9:30am

Pass Type: All Access Pass, Summits Pass

Topic: Programming

Format: Session

Vault Recording: Video

Audience Level: I acknowledge GDC 2021 is an all-digital event and commit to participating virtually.

Procedurally animating an object towards a desired position is ubiquitous in game development. Most developers know lerp, but struggle if lerp doesn't "feel right". When the target point is moving, or when the situation is continuous, instead of transition over a fixed duration, often additional layers of lerp, or other ad-hoc solutions are created. This is unfortunate, because there are many well-studied solutions. This beginner-to-intermediate talk will survey the most important techniques every programmer should have in their toolbox, and give you a framework for thinking about different cases and selecting the best tool for the job.


You'll learn the most important methods for moving an object towards a goal over time. The methods learned in this talk are general purpose tools useful for character control, camera control, transitions, animation of UI elements, and more "feel right".

Intended Audience

This is a beginner talk aimed at programmers, designers, and technical artists. It's best if you have some basic familiarity with linear interpolation (lerp) as that is the starting point for this talk.